package com.sinai.mshab.data;

import java.util.HashSet;
import java.util.Set;

import com.google.gwt.user.client.ui.Widget;

/**
 * A concrete implementation of {@link DataManagerCollection} that delegates
 * work to {@code DataManagerCollection} that are added to it. This is a great
 * class to use if you have multiple {@code DataManagerCollection}s and want
 * all of them to be used.
 * 
 * @author Arthur Kalmenson
 */
public class DataManagerCollectionImpl implements DataManagerCollection {

	/**
	 * The set of {@link DataManagerCollection} to go over.
	 */
	private Set<DataManagerCollection> dataManagerCollectionSet;

	/**
	 * Creates a new {@code DataManagerCollectionImpl}.
	 */
	public DataManagerCollectionImpl() {
		dataManagerCollectionSet = new HashSet<DataManagerCollection>();
	}

	public DataManager<?, ?> getDataManager(Widget widget) {

		DataManager<?, ?> result = null;
		
		for (DataManagerCollection dataManagerCollection : dataManagerCollectionSet) {
			if (dataManagerCollection.hasDataManager(widget)) {
				result = dataManagerCollection.getDataManager(widget);
				break;
			}
		}

		return result;
	}

	public boolean hasDataManager(Widget widget) {
		
		boolean result = false;
		
		for (DataManagerCollection dataManagerCollection : dataManagerCollectionSet) {
			if (dataManagerCollection.hasDataManager(widget)) {
				result = true;
				break;
			}
		}
		return result;
	}

	/**
	 * Adds a {@link DataManagerCollection} for this
	 * {@code DataManagerCollectionImpl} to use.
	 * 
	 * @param dataManagerCollection
	 *            the {@link DataManagerCollection} to add.
	 */
	public void addDataManagerCollection(
			DataManagerCollection dataManagerCollection) {
		dataManagerCollectionSet.add(dataManagerCollection);
	}
}
